•  
  •  
 
Nano Research

Article Title

Ag doped urchin-like α-MnO2 toward efficient and bifunctional electrocatalysts for Li-O2 batteries

Authors

Linna Dai, Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials (Ministry of Education), Research Center for Carbon Nanomaterials, School of Materials Science and Engineering, Shandong University, Jinan 250061, China
Qing Sun, Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials (Ministry of Education), Research Center for Carbon Nanomaterials, School of Materials Science and Engineering, Shandong University, Jinan 250061, China
Lina Chen, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
Huanhuan Guo, Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials (Ministry of Education), Research Center for Carbon Nanomaterials, School of Materials Science and Engineering, Shandong University, Jinan 250061, China
Xiangkun Nie, Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials (Ministry of Education), Research Center for Carbon Nanomaterials, School of Materials Science and Engineering, Shandong University, Jinan 250061, China
Jun Cheng, Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials (Ministry of Education), Research Center for Carbon Nanomaterials, School of Materials Science and Engineering, Shandong University, Jinan 250061, China
Jianguang Guo, Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials (Ministry of Education), Research Center for Carbon Nanomaterials, School of Materials Science and Engineering, Shandong University, Jinan 250061, China
Jianwei Li, Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials (Ministry of Education), Research Center for Carbon Nanomaterials, School of Materials Science and Engineering, Shandong University, Jinan 250061, China
Jun Lou, Department of Materials Science and Nano Engineering, Rice University, Houston, Texas 77005, USA
Lijie Ci, Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials (Ministry of Education), Research Center for Carbon Nanomaterials, School of Materials Science and Engineering, Shandong University, Jinan 250061, China School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China

Keywords

Li-O2 batteries, Ag doped urchin-like MnO2, electronic structure, cycling stability

Abstract

Rechargeable Li-O2 batteries (LOBs) have been receiving intensive attention because of their ultra-high theoretical energy density close to the gasoline. Herein, Ag modified urchin-like α-MnO2 (Ag-MnO2) material with hierarchical porous structure is obtained by a facile one-step hydrothermal method. Ag-MnO2 possesses thick nanowires and presents hierarchical porous structure of mesopores and macropores. The unique structure can expose more active sites, and provide continuous pathways for O2 and discharge products as well. The doping of Ag leads to the change of electronic distribution in α-MnO2 (i.e., more oxygen vacancies), which play important roles in improving their intrinsic catalytic activity and conductivity. As a result, LOBs with Ag-MnO2 catalysts exhibit lower overpotential, higher discharge specific capacity and much better cycle stability compared to pure α-MnO2. LOBs with Ag-MnO2 catalysts exhibit a superior discharge specific capacity of 13,131 mA·h·g−1 at a current density of 200 mA·g−1, a good cycle stability of 500 cycles at the capacity of 500 mA·h·g−1. When current density is increased to 400 mA·g−1, LOBs still retain a long lifespan of 170 cycles at a limited capacity of 1,000 mA·h·g−1.

Graphical Abstract

Publisher

Tsinghua University Press

Share

COinS